Plans for the station were first made in December 1848 under the direction of George Turnbull, resident engineer for construction of the first 20 miles (32 km) of the Great Northern Railway out of London.[8][9] The detailed design was by Lewis Cubitt, the brother of both Thomas Cubitt (the architect of Bloomsbury, Belgravia and Osborne House), and of Sir William Cubitt (who was chief engineer of The Crystal Palace built in 1851, and consulting engineer to the Great Northern and South Eastern Railways). The design is magnificent in its simplicity, being based on two great arched train sheds, with a brick structure at the south end designed to reflect the main arches behind. In size, it was inspired by the 180 metre long Moscow Riding Academy of 1825, which it handsomely exceeded at 246 metres. At the time King's Cross station was the last word in functional modernity. Lewis Cubitt was also responsible for the design of the Great Northern Hotel (see below), and the 1847 cast-iron railway bridge over the River Nene at Peterborough.

The main part of the station, which today includes platforms 1 to 8, was opened on 14 October 1852. The platforms have been reconfigured several times. Originally there was only one arrival and one departure platform (today's platforms 1 and 8 respectively), with the space between used for carriage sidings. As suburban traffic grew additional platforms were added in the 1860s and 1870s with considerably less grandeur. The suburban station building now containing platforms 9–11 is from that era.

A new platform, numbered 0, was opened in 2010. To the east of platform 1, it created capacity for Network Rail to achieve a phased refurbishment of platforms 1–8 that includes new lifts to a new footbridge between the platforms. By 2013 the entire station will have been restored and transformed.[10]

A number of famous trains have been associated with King's Cross, such as the Flying Scotsman service to Edinburgh, and the Gresley A3 and later streamlined A4 Pacific steam locomotives, which handled express services from the 1930s until the early 1960s. The most famous of these was Mallard, which still holds the world speed record for steam locomotives (set in 1938).

In 1972, a single-storey extension designed in-house by British Rail was built on to the front of the station to contain the main passenger concourse and ticket office. Although intended to be temporary, it still stood 40 years later, obscuring the Grade I-listed[11] façade of the original station. Before the extension was built, the façade was hidden behind a small terrace of shops. The extension was demolished in late 2012,[12] revealing once again the Lewis Cubitt architecture. In its place, the 75,000 sq ft King's Cross Square was created, which was opened to the public on 26 September 2013.[13]

On 10 September 1973, a Provisional IRA bomb exploded in the booking hall at 12.24, causing extensive damage and injuring six people, some seriously. The 3 lb (1.4 kg) device was thrown without warning by a youth who escaped into the crowd and was not caught.[14]

In 1991 British Rail proposed a new station under Kings Cross, with four platforms for international trains through the Channel Tunnel, and four for Thameslink trains, with some commuter trains to be diverted to St Pancras. These plans were abandoned in favour of the international trains using a new terminal at St Pancras.[16]

When the railways were privatised in 1996, express services into the station were taken over by GNER. Though it successfully re-bid for the franchise in 2005, it was asked to surrender it in December 2006. National Express East Coast took over the franchise on 9 December 2007 after an interim period when GNER ran trains under a management contract. In July 2009, it was announced that National Express was no longer willing to finance the East Coast subsidiary and the franchise was taken back into public ownership, handing over to East Coast in November 2009.

Class 105 at Kings Cross, York Rd station on the last day of diesel services to Moorgate

Between 1863 and 1976, part of King's Cross was an intermediate station. On the extreme east of the site was King's Cross York Road, with suburban trains from Finsbury Park calling here, then using the sharply curved, and sharply graded York Road Tunnel to join the City Widened Lines to Farringdon, Barbican and Moorgate. In the other direction, trains from Moorgate came off the Widened Lines via the Hotel Curve, with platform 16 (latterly renumbered 14) rising to the main-line level. Services to and from Moorgate were diverted via the Northern City Line from August 1976.[17]

Started in 1855 and opened in 1861 just north of the main station on the Islington side, was constructed a facility for taking coffins and mourners away from the city to the burial grounds at New Southgate Cemetery. This was similar in function to the London Necropolis railway station which was adjacent to Waterloo station in the south but was intended to be a cheaper, more affordable service. The station was at the road level, with coffins lowered by hydraulic lift to the railway level. It never made a profit and was closed in 1873 after just twelve years in operation.[18]

Platforms 5 to 8 of the westerly of the two refurbished train sheds in 2015

King's Cross departures concourse in 2012

In 2005, a £500 million restoration plan was announced by Network Rail; it was approved by Camden London Borough Council on 9 November 2007.[19] The plan includes a thorough restoration and reglazing of the arched roof of the original station and the removal of the cramped and congested 1972 extension, to be replaced by an open-air plaza, scheduled for completion in 2013.[20][21]

A new semi-circular departures concourse, opened to the public on 19 March 2012,[22][23] has been built in the space directly to the west of the station behind the Great Northern Hotel, some outbuildings of which have been demolished. Designed by John McAslan and built by Vinci,[24] it is intended to cater for much-increased passenger flows and provide greater integration between the intercity, suburban and underground sections of the station, facilitating interchange between King's Cross and St Pancras. Departing passengers use the new concourse; arriving passengers initially exited the station from the old concourse on Euston Road, but now go through the new public square. The architect claims that the roof is the longest single-span station structure in Europe. The semi-circular building has a radius of 54 metres and over 2,000 triangular roof panels, half of which are glass.[20]

The steel structure of the roof, engineered by Arup, has been described as being "like some kind of reverse waterfall, a white steel grid that swoops up from the ground and cascades over your head".[20]

Platform 6 after the refurbishment

The land between and behind the two stations is being redeveloped with nearly 2,000 new homes, 486,280 m2 (5,234,000 sq ft) of offices and new roads as King's Cross Central.

As part of this restoration programme, refurbished offices have opened on the east side of the station to replace the ones lost on the west side, and a new platform 0 opened underneath them on 20 May 2010. To prevent exhaust fumes from entering the ventilation system, no diesel trains are permitted to use this platform. The platform occupies the space of a former taxi rank, and was originally to be known as platform Y, but was renamed to avoid the confusion of having both lettered and numbered platforms. When the refurbishment is complete, all the platforms will be renumbered, the new one becoming platform 1.[25] Although there have been plans for a new platform for some time to increase capacity, it was the need to minimise disruption during restoration when other platforms would be temporarily out of use that led to this being built.

King's Cross is used in signage at the Network Rail and London Underground stations, on the tube map and on the official Network Rail webpage.[28] It has been used on official maps from Underground companies since 1951 – the apostrophe was used on them only very rarely before 1951.[29]

Kings Cross is used in the National Rail timetable database and other National Rail railway pages, and on the thetrainline.com online booking system.[citation needed]

Kings X, Kings + and London KX are abbreviations used in space-limited contexts.

The station serves inter city routes to the East of England, Yorkshire, North East England and eastern and northern Scotland, connecting to major cities and towns such as Cambridge, Peterborough, Hull, Doncaster, Leeds, York, Sunderland, Newcastle, Edinburgh, Glasgow, Bradford, Aberdeen and Inverness.

King's Cross St Pancras tube station is served by more lines than any other station on the London Underground, and is one of the busiest. It is in Travelcard Zone 1.

Major work is ongoing to link the various entrances to two new ticket halls and reduce overcrowding. Overcrowding has led to the closure of the entry and exit to the main ticket hall from inside King's Cross during weekday morning peak hours. At these times access to the tube station is via the new entrances outside King's Cross. Staff are placed at these entrances throughout the morning peak to implement crowd control and narrow or close the entrances. None of the other entrances to the tube station can be closed, being either inside St Pancras or too close to Euston Road to allow room for large crowds to wait.[citation needed]

The area of King's Cross was previously a village known as Battle Bridge which was an ancient crossing of the River Fleet. The original name of the bridge was Broad Ford Bridge. The name "Battle Bridge" is linked to tradition that this was the site of a major battle between the Romans and the BritishIceni tribe led by Boudica, Britain's Warrior Queen. Boudica's legendary fame during the Victorian era, when Queen Victoria was portrayed as her 'namesake',[36] restored a historical and cultural foundation to Britain. Boudica has since remained an important cultural symbol in the United Kingdom. The absence of native British literature during the early part of the first millennium means that Britain's native cultural and historical knowledge of Boudica's rebellion, with anything else of pre-Roman occupation, is solely due to the deliberate erasure of indigenous culture with the subsequently revised public image transformed from the propaganda writings of Romans. With scarce historical evidence it is disputed by modern historians. However Lewis Spence's 1937 book "Boadicea – Warrior Queen of the Britons", went so far as to include a map showing the positions of the opposing armies.

According to folklore,[37] King's Cross is the site of Boudica's final battle and perhaps she is buried under one of the platforms. Platforms 8, 9 and 10 have been suggested as possible sites. There are also passages under the station that her ghost is reputed to haunt.

The station, its surrounding streets and the railway approach feature prominently in the 1955 Ealing comedy film The Ladykillers. In the story, a gang robs a security van near the station and Mrs Wilberforce, an elderly widow in a house overlooking the railway, unwittingly assists them in moving the proceeds through the station. Members of the gang fall out with each other and one by one they all fall or are dropped into passing goods wagons from the parapet of the Copenhagen Tunnel a mile to the north of the station.

Platforms 9 and 10 are in a separate building from the main station, and they are separated by two intervening tracks.[38] Rowling intended the location to be in the main part of the station, but she misremembered the platform numbering. In a 2001 interview, she indicated that she had confused King's Cross with Euston, but platforms 9 and 10 at Euston are also separated by two tracks.[39]

Within King's Cross, a cast-iron "Platform 9¾" plaque was erected in 1999, initially in a passageway connecting the main station to the platform 9-11 annex. Part of a luggage trolley was installed below the sign: the near end of the trolley was visible, but the rest had disappeared into the wall. The location quickly became a popular tourist spot amongst Harry Potter fans. Crowding problems in the passage after the release of the first movie resulted in the trolley being removed and the plaque being relocated in 2002 to a bricked up entryway to platform 9 on the exterior wall of the station annex. A new trolley was added to the new location in 2003. The sign and a revamped trolley, complete with luggage and bird cage, were relocated again in 2012, following the development of the new concourse building.[citation needed]

"King's Cross" is the title of Chapter 35 of Harry Potter and the Deathly Hallows, which is set in a dream location resembling the station. The station also features in the epilogue of the book, making it the final setting of the Harry Potter series. The real station appears in the film adaptation of both scenes.[citation needed]

There is an underground station called King's Cross on the North London System in the 1980 novel The Horn of Mortal Danger. It corresponds to this station rather than the tube station.

In the Rev. W.V. Awdry's Railway Series of children's books, Gordon, Duck and an engine from "the Other Railway" have a lengthy argument about the name of the London station (apparently not realising that there is more than one railway station in London). Gordon says it's called King's Cross, but Duck insists that the name is Paddington (because he worked for the GWR) and the visiting engine believes it to be Euston. Desperate to prove himself right, Gordon tries to go to London himself and finally succeeds. However, on his return from St Pancras he laments that his destination was "all wrong."

In the 1933 film Friday the Thirteenth,[40] King's Cross is the used location to introduce two of the main characters. The name of the station is emphasised in the dialogue.

The Pet Shop Boys released a song entitled "King's Cross" on the 1987 album Actually. The station was extensively filmed in for the Pet Shop Boys feature film released in 1988, It Couldn't Happen Here.

In their music video "Rent" (1987), King's Cross is used extensively as a backdrop. The concourse is the meeting point for Chris Lowe and Margi Clarke playing characters who are reunited in front of the departures and arrivals board. In the background are notices stating that engineering work will disrupt services, which at the time (1987) was in progress to modernise the line. Parked outside in the taxi rank is Neil Tennant, playing Margi Clarke's taxi driver.

The song "Who Was That Man" on Nick Lowe's 1991 recording Party_of_One refers to an unidentified victim of the King's Cross Fire.